The present invention relates to a cleaning machine for metal parts comprising a basket, grate or similar foraminated container for receiving the metal parts, rigidly mounted for rotation on a rotating wheel or rotor, the driving of which is effected by means of one or more jet nozzles acting on said wheel or rotor, through which nozzles a fluid under pressure is passed, and means for maintaining constant the rotation speed of said wheel.
In the art of metal processing and in particular in workshops for repair and maintenance, service-stations or garages, cleaning machines for cleaning metal parts are known fulfilling the task of a washing machine, that is to say to clean metal parts from adhering soil, dirt, grease, fat or other pollution. Within the machine is provided a basket, grate or similar metal parts receiving foraminated container, resting on a rotating wheel, which is driven into rotation. In the machines thusfar known the rotating wheel is driven by means of the jet from a spray nozzle acting on the spokes of the rotating wheel to the effect that the wheel starts rotating.
In machines of simple construction the speed of the rotating wheel is controlled manually by means of a simple handle and monitored visually, said handle being operated when-ever an inspection of the speed indicator shows that the actual speed deviates from the normal value. In the event that the speed is too low the pressure of the fluid leaving the nozzle is increased, and in the opposite case the pressure is reduced.
There have also been known machines, in which the rotating wheel can be driven by two pressurized spray nozzles, either in a clock-wise or anti-clockwise direction. The rotation direction and rotation speed required can be controlled continuously via a manually operated differential valve, the rotation speed and rotation direction being clearly indicated on a corresponding instrument. In this known construction the fluid pressure is transferred differentially to both spray nozzles by the intermediary of the differential valve permitting a limitation of the rotation speed.
However, this known device still requires a careful adjustment of the spray pressures by means of the differential valve, so that a convenient operation of the machine depends on the carefulness of the operator. It must be ensured that in any circumstance, depending on the loading weight of the metal parts to be cleaned, carried by the rotation wheel, the fluid pressure needed can be achieved so as to drive the rotating wheel at the rotation speed desired. It should be noted that if this rotation speed increases, there is a risk that due to centrifugal forces metal parts will be flung out of the grate, which may result in damaging of the machine.
It is desirable in machines of this type that the grate proper have a constant rotation speed of say 30 revolutions per minute, permitting on the one hand a satisfactory cleaning effect, and on the other hand a positioning, without danger, of the metal parts.